The present invention relates to a matrix-type switch with several layers of crossing points which is especially usable in telephone switching or other signal distributor systems, or in similar devices. More particularly, the invention relates to such a switch with selection being made by coordinates.
The switch described in European Patent Application No. 80401188.0 (U.S. patent application Ser. No. 174,790, filed Aug. 4, 1980, and its continuation Ser. No. 379,058, filed May 17, 1982) is formed of several first layers of parallel wires, oriented in a first direction, and of several second layers of parallel wires oriented in a direction perpendicular to the first layers, the first and the second layers of wires being intercalated relative to one another. Each layer of wires is supported by or within a grid of insulating material having a square mesh. Each mesh opening has a conductor wire running through it, the wire being parallel to one of the sides of the mesh opening.
The grids of the second layers (i.e. even numbered grids) are angularly shifted by one quarter of a rotation, all in the same direction, relative to the position of the grids of the firt (i.e. odd numbered grids) layers (i.e. the wires of the odd and even numbers are orthogonally related). One crossing point is constituted by two superposed adjacent meshes and a conductor surface of a plug, the axis of which is perpendicular to the plane of the layers, and which is plugged into the meshes of the crossing point. The plug makes it possible electrically to connect the wire segment of the upper mesh to the wire segment of the lower mesh.
Each plug which is plugged into a pile of crossing points is fitted with as many conductor cylindrical rings as there are crossing points being superposed. Each ring has a height chosen to constitute the conductor surface of a single crossing point. In some cases, the conductor surfaces of the plugs are constituted only by ring sectors. The plugs comprise crescent-shaped heads, the horns or points of which cooperated with the flexible teeth of the selection bars which can be deformed by the teeth of the work bars.
The selection and work bars are crossed (i.e. they are perpendicular to each other). Each selection bar can be pushed in one direction thus determining, together with a working work bar, the rotation of a plug head by one quarter of a rotation in one direction. The selection bar can be pulled in the other direction, thus determining, with an adjacent work bar, the rotation of the same head by one quarter of a rotation in the other direction. The rotation of the plug in one direction or in the other direction causes the conductor sectors of the rings of the plug to set or to break the connections of the piled-up crossing points.
In the other case, the conductor surfaces of the rings are constituted by complete circular rings and the closing or the opening of the crossing points is obtained by longitudinally displacing the plugs in a direction perpendicular to the plane of the layers, either in one direction, or in the other.
Thus, in the switch described in European Patent No. 80401188.0, in each couple of grids required to form a crossing point, a plug is wedged or held by the two sides of the insulating superposed meshes. The plug is so held by the wire of a mesh which constitutes a third side, and by the perpendicular wire of the other mesh which constitutes the fourth side. The plug thus is held in place by two rigid sides and by two flexible sides. The space existing between the conductors and the sides of the adjacent meshes are wasted. As, in addition, the widths of the mesh sides are relatively more important than the widths of the conductor wires, the results of that arrangement is that, in a grid, more than half the useful surface is lost.